ETC DHW2805S

DHC2800S SERIES 7.5W DC-DC CONVERTERS
DHW2805S
M I C R O T E C H N O L O G Y
HTTP://WWW.APEXMICROTECH.COM
(800) 546-APEX
(800) 546-2739
HI-REL DESIGN
•
•
•
•
WAVE SOLDERABLE PACKAGE
ALL CERAMIC CAPACITORS
SURFACE MOUNT MAGNETICS
WITHSTANDS 5000G
FEATURES—SINGLE OUTPUT
•
•
•
•
•
•
•
NO DERATING — –55° C to +125° C
SUPPLY RANGE — 16V to 40V
HIGH ISOLATION — 500V
HIGH POWER DENSITY — 21W/IN3
OUTPUT VOLTAGE ADJUSTMENT STANDARD
REMOTE SHUTDOWN
OPERATES 11 TO 50VIN AT 5W
Package Dimensions
1" W x 1" L x .35" H
TYPICAL APPLICATION WITH OPTIONS
10nF
8
DESCRIPTION
The DHW2805S DC-DC converter is a high performance
version of our standard DHC2805S converter. This converter
provides the ruggedness, reliability, and features required to
meet the advanced design challenges of today’s hi-rel market.
This is accomplished while retaining a power density of 21 W/
in3 and 525 mW/gram of power/package performance. The
use of advanced substrate and reflow soldering techniques
during construction results in a rugged, cost-effective, and
completely solderable package.
DHW2805S hybrid converter utilizes all ceramic capacitors
and surface mount magnetics to provide reliable operation at
all operating temperatures while surviving very high G forces.
DHW2805S standard features include output fault monitoring and/or turn on voltage point programming via the shutdown
pin. All three functions may be implemented simultaneously
with a minimum of external components. An output voltage
adjustment / load compensation pin is also standard however
DHW2805S may be ordered without this feature (/F option).
Fault tolerant design protects these converters from most
external circuit faults. The output and output adjust pins will
withstand +35 V while the shutdown pin will withstand +50 V
protecting the converters from a variety of system or board
faults i.e. solder bridges etc. Unique load fault protection
circuitry allows this converter to pull up loads having difficult
static load line characteristics and allows short term load
excursions significantly beyond ratings in most applications.
A transformer isolated forward converter topology operating
at a switching frequency of 400 kHZ allows operation over a
wide input voltage range. Internal filtering of both input and
output eliminates the need for external capacitors in many
applications.
The 8-pin DIP package (see Package Outlines) is hermetically sealed and isolated from the internal circuits. Heat sinking
is recommended for full power operation at elevated ambient
temperatures.
3
+V
1
DHW2805S
50K
2
VTRIM
5
SET UV
LOCKOUT
7
6
–V
Control
System
RSP
+5V
200K
VIN
5K
SHUTDOWN
OPTO
J174
OPERATION
NORMAL
(TTL)
BLOCK DIAGRAM
6
1
2
5
PWM
FEED FORWARD
CONTROLLER
7
ERROR AMPLIFIER
REFERENCE AND
ISOLATION
3
EXTERNAL CONNECTIONS
+ OUTPUT
1
– OUTPUT
2
ADJUST/COMP*
3
NO CONNECTION
4
SHUTDOWN PLUS
5
TOP
VIEW
8
CASE
7
– INPUT
6
+ INPUT
* Optional N/C on DHW2805S/F
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected]
Powered by ICminer.com Electronic-Library Service CopyRight 2003
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
DHW2805S
ABSOLUTE MAXIMUM RATINGS
INPUT VOLTAGE RANGE (Pin 7 to 6 or 5)
INPUT TRANSIENT (Pin 7 to 6)
OUTPUT WITHSTAND (Pin 2 to 1 or 3)
OUTPUT CURRENT (Continuous)
TEMPERATURE, Storage
TEMPERATURE, Pin Soldering 10s
0-50Vdc
80V @ 50ms
35Vdc
1.5Adc
–65°C, 150°C
300°C
SPECIFICATIONS
PARAMETER
TEST CONDITIONS1
MIN
TYP
MAX
UNITS
STEADY STATE
CHARACTERISTICS
INPUT VOLTAGE RANGE
OUTPUT VOLTAGE
OUTPUT CURRENT
VIN; min ↔ max Vdc @ IMIN
VIN; min ↔ max Vdc
16
5.00
120
28
5.05
40
5.1
1500
Vdc
Vdc
mAdc
EFFICIENCY
OUTPUT RIPPLE VOLTAGE
INPUT RIPPLE CURRENT
Bandwidth 10kHz ↔ 1MHz
Bandwidth 10kHz ↔ 1MHz
64
68
40
40
100
100
%
mVrms
mArms
OUTPUT POWER2
LINE REGULATION
LOAD REGULATION
VIN; min ↔ max3
IOUT; min ↔ max3
6
10
7.5
15
25
W
mVdc
mVdc
125
45
2.5
%/°C
°C
mAdc
mAdc
TEMPERATURE COEFFICIENT
TEMPERATURE RANGE, case2
QUIESCENT CURRENT
INHIBITED
IOUT = 0A
Vpin5; < 8Vdc
ISOLATION CHARACTERISTICS
(input/output/case)
LEAKAGE RESISTANCE
LEAKAGE CAPACITANCE
VTEST = 500Vdc
f = 10kHz
DYNAMIC CHARACTERISTICS
LINE STEP RESPONSE
VOLTAGE CHANGE
RECOVERY TIME (95%)
LOAD STEP RESPONSE
VOLTAGE CHANGE
RECOVERY TIME (95%)
DYNAMIC CHARACTERISTICS
START-UP OVERSHOOT
SHUTDOWN DELAY
SHUTDOWN RECOVERY TIME4
NOTES:
CAUTION
1.
2.
3.
4.
.6
.006
–55
VIN; TR, TF = 10µs
VIN; 16 ↔ 40 Vdc
IOUT; TR, TF = 10µs
IOUT; 50% ↔ max Adc
VIN; 0-50 Vdc
VPIN5; > 10Vdc → <8Vdc
VPIN5; < 8Vdc → > 10Vdc
.09
38
1.25
100
60
MΩ
pF
300
30
mV
µs
700
40
mV
µs
0
220
60
400
500
ms
mV
µs
Unless otherwise stated: TC = 25°C, VIN = 28V, IOUT = IOUT MAX.
Derate power linearly to zero from 125°C to 135°C.
Regulation measured between pin 1 and pin 2 1/6" from case.
Recovery spec assumes that converter has been OFF for at least 500ms.
The internal substrate contains beryllia (BeO). Do not break the seal. If accidentally broken, do not crush, machine, or
subject to temperatures in excess of 850°C to avoid generating toxic fumes.
PACKAGE THERMAL SPECIFICATIONS
RESISTANCE, case to air
TEMPERATURE RISE, junction to case
MIN
TYP
MAX
UNITS
30
15
20
°C/W
°C
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
Powered by ICminer.com Electronic-Library Service CopyRight 2003
APPLICATION
INFORMATION
DHW2805S
OUTPUT ADJUST / COMP
LOAD FAULT RESPONSE
The output voltage of the DHW2805S may be adjusted
from 90% to 110% of nominal value by the use of a 50kΩ
potentiometer as shown. Adjustment beyond this range is
possible however certain characteristics of the converter such
as but not limited to input voltage range, efficiency, ripple and
temperature performance will change. Characterization by the
user is recommended in such applications.
The Apex families of DC-DC converters share load fault
philosophies. Load fault conditions include short-circuit and
severe overload conditions. The DHW2800 converter series
responds to load faults by turning off all power conversion
circuits for 250 mS and then attempting to restart for 10 mS
(typical). The net "on" duty factor during a fault is very low
resulting in low converter dissipation and immunity from
overheating at 125°C. Current beyond rated can flow into the
load at startup time. This allows the converter to bring up
capacitive and other difficult load types more reliably than
competing converters.
3
1
2
50K
10nF
Vo
O
Adjust/comp (pin 3) may be driven by external circuitry
referenced to pin 2 (-output) if desired. Grounding pin 3 causes
voltage to increase (25% typically) while driving pin 3 above
1.3 V causes output voltage to decrease. Pin 3 may be driven
through 10KΩ or more if connection of the comp function is
also required.
The comp function of pin 3 allows capacitive loads as large
as 1000 µF to be accommodated on the DHW2805S without
loss of stability. This feature may be utilized by connecting a 10
nF capacitor between pins 3 and 1. This is generally recommended when low esr load capacitances of 100 µF or greater
are used.
Io
O
NORMAL
LOAD FAULT
NORMAL
TIME
SHUTDOWN PLUS
Pin 5 is used for remote shutdown, output fault detection,
and/or setting the input voltage point at which the converter will
turn on as shown in the typical application diagram. No
connection to pin 5 is necessary for normal operation of the
converter. Pin 5 is referenced to the –input (pin 7).
Shutdown may be implemented by simply connecting pin
5 to an open collector logic output or switch rated at 2.5 mA, 25
Vdc or higher.
Input voltage turn on point is programmed with a single
resistor from pin 5 to 7. An input turn on/off hysteresis (typically
3.5% of Vin) will be observed. This should be considered when
making or verifying set point adjustment. The value of the
setpoint resistor may be determined by the following:
3
R = 210 • 10
ETO – 9.5
(±10% accuracy at 25°C)
Set point temperature coefficient is typically +400ppm/°C.
Output fault monitoring is accomplished by observing pin 5
with a high impedance monitoring circuit. Pin 5 voltage drops
from over 10 V to below 1 V when a load fault causes the
converters fault protection circuitry to activate. It will remain
low for at least 100 ms and return high. If the load fault is still
present pin 5 will return low and the cycle will repeat. A resistor
> 400 kΩ from pin 5 to 7 provides pull down for pin 5 if there is
no input setpoint programming resistor already in place.
This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.
DHW2805SU REV. B JANUARY 1999 © 1999 Apex Microtechnology Corp.
Powered by ICminer.com Electronic-Library Service CopyRight 2003